In the prior art, for example, the patent document CN2605419Y filed on Mar. 3, 2004 discloses a long life brake, which is constituted by a braking portion and a driving unit. The disclosed driving unit structure comprises a driving device and an oil pump as well as an oil storage tank and an oil hydraulic cylinder driven by the driving device, an inlet of the oil pump is communicated with the oil storage tank, an outlet of the oil pump is communicated with a driving oil cavity of the oil hydraulic cylinder. A piston rod, i.e. a push rod is used for the hinge connection of driving mechanisms in the braking portion, and the driving unit is operated so that the braking portion achieves the operation state (brake on or brake off mode).
The existing driving unit has following shortages: since the driving unit is used for keeping the operating state of the braking portion during the operating process, the driving device of the driving unit is required to under operating state all the time so that the oil pump continuously operates to maintain the operating state of the braking portion, thus the energy consumption is large. Further, the temperature rise of the driving device is high due to the driving device being under the operating state all the time, thereby each component of the driving unit is heated. Besides, such heating may be easy to cause aging of sealing members, such that the life span is affected, and in extreme cases the oil leak can be caused, and the workload in maintaining and repairing of the brake is increased.
In addition, braking off mode of the braking operation state of the braking portion is achieved by stopping the operation of the driving device. When cutting off the power supply of the driving device, since the driving device has an operation inertia, there is a postpone time from the cutting off of the power supply to completely stopping of the operation, therefore, the releasing of operation state of the braking portion is caused slow and it is unable to satisfy an operation demand in the case where a rapid braking off is required.